The present disclosure relates to a power system, a power receiving apparatus, and a power transmission control method.
The global environmental problem has become more serious in recent years, and various countries have commenced a number of environmental measures. In this state, attention is being focused on power generation methods that use renewable energy, such as solar, wind, and geothermal power, and power generation methods that use resources with a low environmental impact, such as biomass-powered generation and fuel cells. At present, electricity is mainly generated by thermal power generation using fossil fuel such as oil and coal, nuclear power generation using nuclear fuel, and hydroelectric power generation using water flow.
Nuclear power generation and hydroelectric power generation generate electricity with a low environmental impact. However, with nuclear power generation, there is the accompanying risk and difficulty of safely managing nuclear fuel. Use of hydroelectric power generation meanwhile is limited to regions with the appropriate geographical conditions that enable dam construction and the like. Thermal power generation also has many problems such as the depletion of fossil fuels and the emission of CO2 and NOx that are produced when fossil fuel is burnt.
In response to such problems, research is advancing into methods of replacing much of the electricity traditionally provided by nuclear power, hydroelectric power, thermal power generation, and the like with electricity produced from renewable energy or resources with a lower environmental impact.
Also, in recent years, individual consumers themselves have become increasingly aware of the global environmental problem and have begun to install power generating apparatuses (hereinafter, green power generating apparatuses) that use renewable energy or resources with little environmental impact in their homes. Also, to overcome the instability of supply that is the weakness of power generation methods based on renewable energy, there are also moves toward installing power storing apparatuses along with green power generating apparatuses. It is hoped that in the near future, individual power consumers will generate power in their own homes and consume such generated power themselves.
However, methods that use renewable energy or resources with little environmental impact have a comparatively high power generation cost compared to thermal power generation and the like in typical use today. Accordingly, green power generating apparatuses have yet to become sufficiently widespread in spite of the growing environmental concern and subsidies from governments and the like. For this reason, moves are being made towards providing monetary value (hereinafter referred to as “additional environmental value”), which acts as compensation for the user paying extra to protect the environment, to power (hereinafter, green power) generated by a green power generating apparatus.
That is, securitization of the additional environmental value is being investigated. For example, an arrangement where a suitable number of tradable bonds (hereinafter “green power bonds”) are issued in accordance with the generated amount of green power has been proposed (see for example, Japanese Laid-Open Patent Publication No. 2007-89317). However, various problems exist for the realization of such an arrangement for issuing green power bonds. One of such problems is that there is no framework for certifying the “greenness” (i.e., the environmental impact) of the resources used to generate power. On the other hand, Japanese Laid-Open Patent Publication No. 2002-112458 discloses the configuration of a power supplying system equipped with a means for calculating the greenness of green power.